At present, the road lamp is a familiar lamp. The traditional road lamp is usually made with a halogen lamp, such as a sodium lamp, which have high power consumption, short service life and low light efficiency. For example, in FIG. 1, a structure diagram of a traditional road lamp with uncovered back is shown. The traditional lamp holder comprises a housing assembly 100, a reflector 200, a sodium light source 300, a sodium light electric source 400, and a glass protection diffuser 500. LEDs, such as LED road lamps, have been more widely applied due to their advantages of high light efficiency, long service life and low power consumption. In considering heat dissipation, their radiators are exposed, and the traditional lamp is so small due to LEDs own small volume, thereby current road lamps' shape are strange and monotonous.
Also for a district using a traditional road lamp, it is necessary to disassemble entirely if a currently used LED road lamp is to be replaced; for example, if one cannot use an traditional road lamps' holder any more but needs to use a new LED road lamp holder. So this will cause repeated investment and waste. And if the improved LED road lamp was broken, it is necessary to use a new LED road lamp holder to replace and then disassemble and take back to check. It will be much trouble to maintain with low efficiency and high cost.
Also, the applicant has used an above mentioned method to develop a high power LED road lamp, but radiating air can not directly outflow to outside. Even if the air flows circularly and is convective, it also needs to heat change through outer casing and outer air. This will cause high temperature on outer casing as well as inner casing, and heat cannot dissipate.
When an LED is applied for daily lighting and to achieve lighting requirements, it is necessary to centralize multi-power LEDs to one lamp, so LEDs heat dissipation is a most important element to affect LED lamp use condition and service life, especially for a high power LED lamp. Heat dissipation has become a technological difficulty for wide application of the device.
A traditional LED lamp is equipped with passive heat dissipation, which uses radiators or similar devices for cooling. So when one needs to improve heat dissipation effects, it is necessary to increase heat dissipation area as much as possible, but this will cause the size of a current LED lamp to become bigger and make the structure more complicated. Also, the heat dissipation effect is unsatisfied. In order to overcome these drawbacks, presented herein are embodiments directed to a combined radiating fan and a radiator, as applied to an LED lamp with initiative heat dissipation and passive heat dissipation, thereby improving stabilization and service life. But in exchange for improving the heat dissipation effect on a high power road lamp, the resulting open structure has poor waterproofing and dustproofing characteristics. Thus application can be restricted by outside and other special conditions. Also it may be necessary to design a much more complicated ventilation structure for increasing heat dissipation.
Currently, thermally conductive silicone and thermally conductive empire cloth are used to conduct heat and insulate between a light source board and radiator. The heat conductivity coefficient for thermally conductive silicone is 3 W/(m·K)-4 W/(m·K), and the heat conductivity coefficient for thermally conductive empire cloth is 2 W(m·K)-3 W/(m·K). Both are unsatisfactory due to low heat conductivity coefficients. Also, thermally conductive silicone is made of an unstable paste so it is difficult to spread evenly between the light source board and radiator. This will cause poor thermal conductivity and reduce insulating properties, thereby causing a short circuit. Thermally conductive empire cloth is easy to transform, and can also be troublesome to install and less efficient.